Europe is rich in history, but the splendid castles, antique churches and age-old ruins tell only part of the story. To dig even deeper in time — much deeper — visit a cave. Some of my favorites, in France and Slovenia, showcase 17-foot-long bulls drawn by our ancient forebears and 100-foot-high stalagmites sculpted by nature.

SISTINE CHAPEL OF THE PREHISTORIC WORLD

The world’s most famous cave paintings are at Lascaux, in southwest France. From 18,000 to 10,000 B.C. — long before Stonehenge, before the pyramids, before metalworking, and before farming — prehistoric people painted deep inside these limestone caverns. These are not crude doodles with a charcoal-tipped stick. They’re sophisticated, costly and time-consuming engineering projects.

Discovered in 1940, the caves were closed to visitors in 1963 due to the deterioration of the artwork. But a “copy cave,” Lascaux II, allows visitors to see the reindeer, horses and bulls of Lascaux, painstakingly reproduced by top artists using the same dyes, tools and techniques their predecessors did 15,000 years ago. Guides call the Lascaux Caves the “Sistine Chapel of the prehistoric world.” I thought, “Promotional hyperbole.” But then I climbed into Lascaux II and was swept away by its grandeur.

Nearby, the Grotte de Font-de-Gaume is the best place to see actual original prehistoric art. Even if you’re not a connoisseur of Cro-Magnon culture, you’ll dig this cave — the last one in France with prehistoric multicolored (polychrome) paintings still open to the public.

Font-de-Gaume contains 15,000-year-old paintings of 230 animals, including many red-and-black bison painted with a moving sensitivity. Your guide, with a laser pointer and great reverence, will trace the faded outline of the bison and explain how, 15 millennia ago, cave dwellers used local minerals and the rock’s natural contours to give the paintings dimension.

Getting in is tricky — only 26 tickets per day can be reserved in advance by email or phone; otherwise, 52 tickets are doled out in person each morning. Try to reserve in early January for a summer visit (for details, see sites-les-eyzies.fr/en/).

UNDERGROUND GEOLOGY LESSON

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In Slovenia, the ancient history found below ground relates to geology, not human culture. About an hour south of Ljubljana, the country’s Karst region is honeycombed with a vast network of caves and underground rivers. Spelunkers agree that this region has some of the most remarkable caves on the planet, including my favorite, the Skocjan Caves.

At Skocjan, visitors begin by seeing a multitude of formations in a series of large caverns. Guides tell the story as, drip by drip, stalactites grow from spaghetti-thin strands to mighty sequoia-like stone pillars. The experience also builds and builds, as you go into ever more impressive grottoes, until you get to the truly colossal final cavern — the “Murmuring Water Cave” — with a mighty river crashing through the mist. It’s a world where a thousand evil “Wizard of Oz” monkeys could comfortably fly in formation. Crossing a breathtaking footbridge 150 feet above the torrent gives you faith in Slovenian engineering. Finally, the cave widens, sunlight pours in, and you emerge — like lost creatures seeking daylight — into a lush canyon.

The nearby Postojna Caves are Slovenia’s most popular tourist attraction. Postojna lacks Skocjan’s spectacular, massive-cavern finale, but the formations at Postojna are slightly more abundant, varied and colorful, with stalagmites and stalactites as tall as 100 feet.

A visit here is an easy, lightly guided stroll through an amazing underground cavern (in contrast to the fairly strenuous hike required at Skocjan). A little open-air train slings you deep into the mountain, whizzing past wonderful formations. Then you walk along a well-lit, paved path up the “Big Mountain,” where you’re surrounded by a sea of fairy chimneys. A bridge over a canyon takes you into “Spaghetti Hall,” named for the long, skinny stalactites that seem to be dripping from the ceiling. After passing some huge, white, melting-ice-cream formations, you’ll wind up in the impressively vast cavern called the “Concert Hall.” Here, an aquarium houses the strange, pale-pink, salamander-like “human fish,” a cave-dwelling creature that is celebrated as a sort of national mascot in Slovenia.

After exploring some of the world’s best caves, mull over what you’ve seen — and return to more modern history — with a glass of local wine from the famous wine regions not far from these caves: Primorska in Slovenia and Bordeaux in France. Raise a glass to red-and-black bison, colossal caverns and human fish that hide beneath Europe’s modern surface.